1. Field of the Invention
The present invention relates to a brake control system for a vehicle. In particular, the present invention relates to such a brake control system which can be mounted on a bar-handle type vehicle such as a motorcycle, a tricycle, and an all-terrain vehicle (ATV).
2. Description of the Background Art
Conventionally, there is a vehicular brake control system electrically controlling brake hydraulic pressure of a vehicle to thereby apply brake force to the vehicle (for example, see Japanese Patent Examined Publication No. JP-B-3457190).
The brake control system disclosed in JP-B-3457190 is structured such that a distribution ratio of the brake forces in the interlocking brakes of the front and rear wheels of a motorcycle is set so as to correspond to an ideal brake force distribution curve. (This interlocking brake is also called as combination brake) Normally, the ideal brake force distribution curve of the motorcycle has a chevron-shaped characteristic that: in a range where the brake force is small, the brake force of the rear wheel rises as the brake force of the front wheel rises, whereas, in a large brake force range, the brake force of the rear wheel decreases as the brake force of the front wheel increases.
In the above-cited vehicular brake control system, not only in a brake applying time but also in a brake releasing time, decompression control is made using the interlocking braking operation of the front and rear wheels corresponding to the ideal brake force distribution curve. Therefore, for example, in a state where the interlocking braking operation is under execution in the vicinity of maximum brake force of the ideal brake force distribution curve, when the brake operating member on the front wheel side is released, there is developed the following characteristic: that is, as the brake force of the front wheel side decreases correspondingly to the ideal brake force distribution curve, the brake force of the rear wheel side reversely tends to increase and, after then, it decreases. In the brake releasing operation where such the characteristic is generated, in a process where the brake forces of the front and rear wheels decrease, there occurs a phenomenon that the brake force on the rear wheel side increases temporarily. This makes a rider feel uncomfortable and thus impairs the riding feeling of the motorcycle.